Temporary Intercropping as a Management Option for Increasing Plant Diversity in Southern Australian Cropping Systems: A Perspective

Australia’s southern cropping systems have limited plant diversity, dominated by cultivation of small grain winter cereals, mainly wheat (Triticum aestivum L) and barley (Hordeum vulgare L.), with a smaller proportion of break crops including canola (Brassica napus L.) and pulse legumes. Synchronous intercropping, where two cash crops are sown and grown together, and harvested simultaneously, could increase plant diversity but adds additional complexities in these highly mechanised farming systems. Temporary intercropping involves multiple plant species being sown together, with all but one species (the cash crop) terminated prior to harvest. This perspective explores temporary intercropping as a management practice to integrate a greater diversity of plant species into the cropping system. The impacts of temporary intercropping on cash crop growth, grain yields, soil health, and nitrogen cycling are reviewed. The ease with which temporary intercropping trials can be implemented through participatory farmer research is demonstrated via two case studies. We conclude that temporary intercropping holds promise as a means by which to introduce greater plant species diversity into Australian southern farming systems, but further research is needed to optimise intercrop species and seeding rates, fertiliser practices, and the timing of intercrop termination before economic assessments can be made.